Moisten enough sphagnum peat moss to fill a 2-inch pot. Add the material to the planter.
Cut the broken stem to a 3- to 4-inch-long cutting if it is longer. Retain at least one dormant bud. Keep track of which side of the stem is the top and which one is the bottom.
Plant the bottom end of the Dendrobium branch in the sphagnum peat moss. Press the material against the base of the stem to hold it in place upright.
Spray the stem and the moss with water at planting. Move the pot to the shade. Continue to maintain the rooting medium and the stem moist.
Separate by hand or with shears the orchid that sprouts from the node after it develops several aerial roots. Plant it in orchid potting mix.